1. Field of the Invention
The present invention relates to waste water treatment systems and more particularly relates to drilling mud reclamation from oil or gas well reserve pit water, wherein the water cleanup process and drilling mud reclamation are performed simultaneously.
2. General Background and Prior Art
In the process of drilling in oil or gas well, it has been a standard practice to erect what is known in the art as a "reserve pit" for storing formation cuttings as well as drilling mud and water spills which occur during the drilling operation.
These spills consist of the waste water spills from oil and gas well drilling operations consist of a number of undesirable compositions, such as chlorides, chronium, zinc, organic or inorganic carbons, and othersuch parameters that cause the waste stream to have a high chemical oxygen demand.
Reserve pits vary in size depending on the depths of the well to be drilled and the length of drilling time anticipated. They may for example cover an area of two square in size.
During the drilling operation, all the fluids spill regardless of their nature are captured and stored in the reserve pit and allowed to accumulate until drilling is completed. Fluid at that time may be disposed of in various manners such as pumping into trucks for removal to dumping sites, burning, or any other types of untreated waste disposal. In fact, a wholesale dumping of the waste into streams and rivers at night when detection by authorities is not reliable has been a problem.
Thus, there is a need for a method of disposing of the waste stream which can process the waste materials in the waste stream removing them from the stream. It will be preferable that the system of cleaning constantly and continuously remove waste materials from the water as the drilling progresses rather than after the entire operation as is presently the case.
It should be understood that a large amount of drilling mud accumulates in the waste stream which is pumped to the reserve pit during drilling operation. Drilling muds which are generically as "barites" are quite extensive and must be purchased by the driller for use in the drilling operation. The reclamation of the costly drilling muds or "barites" on the actual drilling site as the drilling is progressing would be desirable. In this manner, a pollution of streams and rivers adjacent the drilling site would not be a problem and the driller could reclaim the barites and recycle them during the drilling operation instead of having to continuously purchase drilling mud as the well progresses and not recovering any drilling muds until the entire well was completed.
Indeed, it is present practice that the drilling mud be allowed to mix into the waste stream and be collected in the reserve pit and be therefore lost as waste never to be recovered.
In addition to the barites or drilling mud in the waste water stream generated by oil and gas drilling, there is seen as above mentioned several other parameters such as oil, grease, suspended solids, chlorides, chromium, zinc, organic and inorganic compounds and the like.